दो द्रव \(\mathrm{A}\) तथा \(\mathrm{B}\) को मिश्रित किये जाने से प्रेक्षित कुल दाब \(350 \mathrm{~mm} \mathrm{Hg}\) है जब इनके मोल प्रभाज क्रमशः \(0.7\) तथा \(0.3\) है यदि \(A\) तथा \(B\) के लिये मोल प्रभाजो को क्रमशः \(0.2\) तथा \(0.8\) तक परिवर्तित किया जाता है तो कुल दाब \(410 \mathrm{~mm} \mathrm{Hg}\) हो जाता है तो शुद्ध \(A\) का वाष्प दाब_____________  \(\mathrm{mm} \mathrm{Hg}\) है (निकटतम पूर्णाक में) मानें कि द्रव तथा विलयन आदर्श व्यवहार करते हैं

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.